DE2947982B2 - Water-in-oil disintegrant emulsions - Google Patents

Description

The invention relates to water-in-oil disintegrant emulsions having excellent emulsion stability at Storage, detonability at low temperature, explosive effect, safety and sympathetic detonation according to the preceding claims.

So far, the explosive effect (usually expressed by the explosion speed) has been Common disintegrants improved in that 1) the components of the disintegrant have been selected appropriately or 2) the mixing ratio of the Components of the disintegrant has been modified. Method 1) consists in the selection of substances with a high reaction speed or the selection of substances that have a high reaction rate Release thermal energy, d. H. have a large heat of explosion and the like. The method 2) consists in that an oxidizing agent is combined with a fuel in fine-grain form d. H. the contact area increases or these substances with each other in Water dissolves to increase the contact area.

If therefore a water-soluble and a water-insoluble substance in a disintegrant slurry are contained, it is very difficult to bring both substances dissolved in water into contact with each other, so that it is necessary to form a mixed phase in which an aqueous solution of a water-soluble substance and a water-insoluble substance in contact are in a state of both substances Have grain that the contact area is large.

Almost all common disintegrant slurries are oil-in-water emulsions (hereinafter abbreviated to O / W emulsions), in which the water is used as Skin constituent water-insoluble substances or water-soluble substances that are not completely immersed in water soluble and contained in the water, envelops the main part of the water-insoluble substances in the O / W disintegrant emulsions represent oxidizing agents represent, e.g. B. inorganic oxidizing salts such as ammonium nitrate and the like, and the greater part of the water-insoluble substances are fuels or sensitizers, which act together as fuel, for example aluminum, nitromethane and the like

ίο In the case of disintegrant slurries, if the components are divided into water-insoluble substances (hereinafter referred to as "O") and water-soluble substances (hereinafter referred to as "W") be classified based on the weight that Mixing ratio O / W not greater than 25/75. Therefore, assuming that the dispersed Particle size in O / W emulsions and in W / O emulsions is the same as the contact area of O and W for W / O emulsions (water-in-oil emulsions) larger, with O being in a smaller amount, W envelops that is present in larger quantities than with O / W emulsions. Therefore it is to be expected that the The disintegration effect of W / O emulsions is better good post-detonation smoke can be obtained. With regard to increasing the contact area are one Large number of W / O disintegrant emulsions instead of the usual O / W disintegrant emulsions from US Patents 32 12 945, 33 56 547, 34 42 727,

jo 34 47 978.36 74 578.37 65 964 and 37 70 522 become known. In these W / O disintegrant emulsions the quality is influenced to a large extent by the selection of the sensitizing agent to be added to the W / O emulsion In those mentioned above U.S. Patents, the following sensitizers are used in W / O disintegrant emulsions:

Table 1 U.S. Patent Sensitizer Used

3,212,945 nitroglycerin, nitroglycol 3 442 727 Hollow glass microspheres 3 447 978 Hollow glass microspheres,

aluminum

3,765,964 Strontium Salt, Hollow Microspheres of glass

3,356,547 nitroglycerin, nitroglycol 3 770 522 Hollow glass microspheres, Aluminum,

Chemical foaming agent "3,674,578 Amine Nitrate and Gas

Although these various sensitizers have been used, these substances are supreme

_W ) dangerous or have a low initial sensitivity or sympathetic detonation sensitivity. In the case of the disintegrants in which nitroglycerin and nitroglycol are used as sensitizers, the same problem arises in production as

_M in the case of dynamite, and the sensitivity in use is very high, so that it is to be feared that an accidental, unintentional explosion will take place if the sleeve is removed from the drill of a drilling machine

is hit, so that such an explosive is highly It is unsafe to have explosives with strontium salts or an amine nitrate as a sensitizer the former have very little sensitivity and act catalytically in the detonation reaction, so that it can be assumed that the sensitivity is very low and in particular the sympathetic detonation sensitivity is very low. The latter have a high one Water solubility, so that it, in order to increase the sensitivity increase, must be contained in larger quantities, and in the case of large quantities, the quantity of Emulsifiers and oils are small because of the oxygen balance. In this case the ratio will be from volume of oil to volume of aqueous solution is very small, and the formation of W / O emulsion becomes difficult. Even if an emulsion can be formed, because the amount of oil is very small, the stability of the W / O emulsion is very low and the sensitivity is very low. According to the invention These considerations have been taken into account and studied over a long period of time. A W / O disintegrant emulsion with excellent emulsion stability has been found during storage, explosive effect, detonability at low temperature, sympathetic detonation and Security found, as has been the case with W / O emulsions so far has not been possible by incorporating nitromethane, which is much less sensitive than nitroglycerin, nitroglycol and the like, and that too belongs to the water-insoluble substances. At the same time, the W / O emulsion contains bubbles around the Improve contact.

Thus, the invention consists in a W / O disintegrant emulsion, from a) ammonium nitrate or one Mixture of ammonium nitrate and another inorganic oxidizing salt (hereinafter abbreviated to "inorganic oxidizing salt, such as ammonium nitrate"), b) water, c) oil and / or wax, d) a surfactant sorbitan fatty acid ester and e) a density control agent in the form of free or enclosed gas bubbles, characterized by the content of gelled nitromethane, obtained by gelling nitromethane with a suitable gelling agent, as well as hollow microspheres. Instead of the hollow microspheres, those generated by a chemical foaming agent can also be used The vesicles are used or the vesicles formed in this way are used together with hollow microspheres will. In these explosive mixtures, the density is determined by means of the microspheres or gas bubbles set

W / O disintegrant emulsions according to the invention can be prepared in the following way: The inorganic oxidizing salts such as ammonium nitrate are wholly or partially in a Temperature from 55 to 75 ° C dissolved in water to form an aqueous solution A surface-active sorbitan fatty acid ester (emulsifier) and an oil and / or wax are mixed at a temperature of 55 to 75 ° C to form a homogeneous liquid mixture. Then will the aqueous solution and the homogeneous liquid mixture at a temperature of 55 to 75 ° C mixed and stirred whereby an emulsion is obtained. This emulsion with a temperature of 55 to 75 ° C is cooled with stirring, and when the emulsion changes from a transparent to a completely has been converted to a milky state, the stirring is stopped. If not all of the crowd on inorganic oxidizing salts such as ammonium nitrate has been dissolved to an aqueous solution this remainder of oxidizing salts is now added to the emulsion. Then a mixture of the gelled nitromethane obtained by mixing nitromethane with a suitable gelling agent has been added with hollow microspheres when not using hollow microspheres a chemical foaming agent is added, this is before or after the addition of the gelled

ίο Nitromethane added to density-controlling vesicles to obtain. When hollow microspheres are added along with a chemical foaming agent are, the chemical foaming agent before or after the addition of the gelled nitromethane in the added to the first production stage for the production of W / O disintegrant emulsions

In the context of the invention, the following components can be used: Other inorganic ones oxidizing salts, which together η with ammonium nitrate Can be used, nitrates, such as

Sodium nitrate calcium nitrate and the like, chlorates such as Sodium chlorate and the like perchlorates, such as sodium per-

chlorate and the like.

Conductive oil, heavy oil

and the like, paraffin wax, petroleum jelly, microcrystalline wax u. dgL, as well as any mixed: these oils and waxes in any mixing ratio depending on the desired consistency of the disintegrant be used.

As surface-active sorbitan fatty acid esters, which are used as Sorbitan monooleate, sorbitan sesquioleate, sorbitan monopalmitate, sorbitan monostearate and the like may serve as emulsifying agents. These surfactants Sorbitan compounds are not particularly included restricts, but sorbitan monooleate and sorbitan sesqui oleat are preferred.

Technical grade nitromethane can be used as nitromethane. Used as a gelling agent for nitromethane Usually nitrocellulose is effective, but it can

4j acrylic acid ester polymers can also be used.

As hollow microspheres and / or chemical Foaming agent (hereinafter referred to as density controlling The following can be used

are: Hollow microspheres include such

- «, 5 made of glass, made of synthetic resins, made of quartz, made of Shirasu (a kind of quartz) and the like, it is not necessary to use the particularly fine and expensive microspheres but the coarse hollow microspheres with an average particle size of about 500 μπι are completely sufficient. To the chemical Foaming agents include inorganic foaming agents such as a mixture of alkali metal borohydride or sodium nitrite with urea, and organic foaming agents such as N, N'-dinitrosopenta methylentetramine, azodicarbonamide, azobisisobutyro- nitrile and the like

The mixing ratios of these components for the disintegrant emulsion should be determined by maintaining oxygen balance, detonability, Strength consistency and productivity taken into account. In general, 50 to 90% of the inorganic oxidizing salts, such as ammonium nitrate, 5 to 20% Water, 1 to 7% oil and / or wax, 1 to 5% emulsifier, 3 to 20% nitromethane, 0.1 to 3%

b5 Gelling agent for nitromethane, 1 to 10% hollow Microspheres and 0.1 to 2% chemical foaming agent mixed together. The percentages mentioned are percentages by weight.

Coal mine explosives with high degree of safety, the methane gas and coal dust in the mine not ignite, can by adding a flame coolant, such as sodium chloride, potassium dichloride to the W / O disintegrant emulsion according to the invention will.

The invention is explained in detail below by way of examples and comparative examples In the examples, parts and percentages are parts by weight and percentages by weight, respectively. ι ο

When evaluating the W / O disintegrant emulsions According to the comparative examples and the examples, the emulsion stability on storage was by the Temperature cycle test, detonability and the Explosive effect through the initial ignition test at low temperature and the explosion speed carried out at this point The air gap test was carried out on sand at 5 ° C

The temperature cycle test was carried out as follows: A sample was held in a thermostat at ⁰ ° C. for 14 hours and then transferred to a thermostat of 40 ^° C. and left there for 7 hours, which is referred to as a cycle. This was repeated, and the number of cycles at which the W / O emulsion collapsed was determined. Criteria for the collapse of the emulsion were that ammonium nitrate crystals were precipitated and water was deposited on the surface of the disintegrant, and that this phenomenon occurred suddenly. jo

The initial ignition test at low temperature (detonability), the measurement of the explosion speed (Explosive effect) and the air gap test were carried out after a W / O explosive center! - emulsion in a polyethylene tube with a diameter j> of 25 mm and a length of 200 mm was inserted and then the end was closed. The so obtained sleeve was subjected to the temperature cycle test. The ignition test at lower Temperature was carried out by placing the sample in a low temperature thermostat was used to set the sample to the test temperature, and then a probe was used to measure the Explosion speed sunk into the sample and the sample in an unlimited state by means of a 4> electric detonator No. 6 detonated on sand and the explosion speed using a digital computer measured.

The air gap test was expressed by a value determined as follows: The temperature the sample was set to + 5 ° C, and then an initial ignition sleeve and a receiving sleeve, in each of which an electric detonator no. 6 had been fitted in, set on sand at intervals, which were a multiple of the sleeve diameter. Then the primer sleeve was set to detonate the receiving sleeve ignited. As a result of the air gap test, the distance between the primer sleeve and the receiving sleeve as a multiple of the diameter of the sample sleeve. so

The following examples explain the invention in more detail, but do not mean any restriction of the Area of invention.

Comparative example 1

A W / O disintegrant emulsion having the composition shown in Table 2 below was prepared as follows: To 36 parts of water, 160 parts of ammonium nitrate, 40 parts of sodium nitrate and 40 parts of calcium nitrate were added, and the mixture was used to dissolve the nitrates in water and to Obtaining an aqueous solution of the oxidizing salts heated to about 65 ° C. Meanwhile, 8 parts of batyl stearate were added as an emulsifier to 14 parts of light oil No. 12 and the resulting mixture was heated to about 65 ° C. to obtain a homogeneous liquid mixture of emulsifier and oil Solution of the oxidizing salts was gradually added to the homogeneous liquid mixture of emulsifier and oil with stirring at a speed of about 300 rpm by means of a conventional propeller stirrer ° C further stirred The emulsion was at was allowed to stand about 65 ° C, and was decreased as the temperature to about 6O ⁰ C, the emulsion was again stirred at a speed of about 500 rpm as the emulsion from the transparent state to a milky state out, the stirring was stopped and the emulsion was allowed to stand. Abgesunker than the temperature to about 4O ⁰ C, was, 24 parts of hollow glass microspheres was added as a density control agent, thereby obtaining a W / O emulsion explosive.

This was subjected to the temperature cycle test and the initial ignition test at low temperature, the results shown in Table 2 were obtained.

Comparative Examples 2 to 6

In the manner described in Comparative Example 1, W / O disintegrant emulsions with the in Table 2 prepared compositions and the temperature cycle test and the air gap test (only for comparative examples 5 and 6).

example 1

A W / O disintegrant emulsion having the composition shown in Table 2 was prepared as follows Prepared way: To 48 parts of water were 210 parts of ammonium nitrate, 55 parts of sodium nitrate and 55 parts Calcium nitrate was added and the resulting mixture was used to dissolve the nitrates in the water and to dissolve Obtaining an aqueous solution of the oxidizing salts heated to about 65 ° C. During this time, 6 Parts of sorbitan sesquioleate were added to 12 parts of No. 12 light oil and the resulting mixture to form a homogeneous liquid mixture of the emulsifier and the oil is heated to about 65 ° C aqueous solution of the oxidizing salts gradually became the homogeneous liquid mixture Emulsifier and oil added.

This emulsion having a temperature of about 65 ° C was allowed to stand for a certain time, and was decreased as the temperature to 6O ⁰ C, the emulsion was again stirred at a speed of about 500 rpm. When the emulsion had been converted from a transparent to a milky state, the stirring was stopped and the emulsion was allowed to stand until the temperature had dropped to about 40 ° C. At this temperature, gelled nitromethane, which consisted of 72 parts of nitromethane and 4 parts of nitrocellulose, were produced , and 21 parts of hollow glass microspheres were added, one

W / O disintegrant emulsion was obtained. This was the temperature cycle test, the initial ignition test at low temperature and the air gap test subjected. The results obtained are shown in Table 2.

Examples 2 to II
To that described in Example 1

1
W / O disintegrant emulsions with

Way were those in Table 2

specified compositions and the temperature cycle test, the initial ignition test at lower Temperature and the air gap test. The results obtained are shown in Table 2. In Examples 4 and 10, however, the samples were after their preparation for the decomposition and foaming of Ν, Ν'-dinitrosopentamethylenetetramine, to the To reduce density, heat in a thermostat for about 2 hours at about 50 ° C.

rubbed 2u

Comparative example 1 2 3

Example 1 2

10

Composition (%)

Waterless solution of the oxidizing agent

Ammonium nitrate 49.7 Sodium nitrate 12.4 Calcium nitride 12.4 water 11.2 Emulsifier ') (D 2.5 (2) - (3) - (4) - (5) - (6) - (7) - Oils or waxes Light oil No. 2 4.3 unruly. mlcrokr. wax -

49.7
12.4
12.4
11.2

49.7 12.4 12.4 11.2

2.5

4.3 4.3

49.7 12.4 12.4 11.2

2.5

49.7 49.7

12.4 12.4

12.4 12.4

11.2 11.2

2.5

4.3 4.3

43.5
11.4
11.4
9.9

43.5 11.4 11.4 9.9

1.2 1.2 1.2

2.5 2.5 2.5

55.5 55.5 55.5 • ΉΧ.4 60.3 55.5 60.3 14.0 14.0 14.0 14.7 15.2 14.0 15.2

77.3

7.5 9.0 9.0 10.9 4.5 9.8 9.0

1.1

1.) 1.5 1.2 1.1 1.2 K)

1.8 OO 2.3 2.3 2.3 2.9 3.6 2.3 1.8 ¹ ^

Table 2 b

Comparative example 1 2 3

example 1 2

10

Composition (%) Density controlling agent

Hollow microspheres glass resin ^J ) Shirasu

Chemical sponge ¹ )

7.5 7.5 7.5 7.5 7.5 7.5

14.9 14.9 14.9 11.3 13.5 13.5 13.5 8.4 5.4 15.2

0.8 0.8 0.8 0.6 0.7 0.7 0.7 0.4 0.2 0.7

4.4

4.4

0.5

3.9 3.9 2.0 4.2 4.3 2.0

0.2

^^ - aaKsgi ^^

Table 2c evaluation

Comparative example 3 4th 5 6th example 2 3 4th 5 6th -J 8th 9 10 11th 1 2 E.g. E.g. Well Well 1 Well Well Well Well Well Well Well Well Well Well Eg ZB 4th 3 10 10 Well 10 IO 10 10 10 10 10 10 10 10 3 4 10

Stability according to temperature ZB cycle ⁴ )

Quality according to the temperature cycle

Detonable barrage

Initial Zdg. at low Temp. ⁵ )

Explosive effect

Explosion speed m / s ⁵ )

Air gap test value ⁷ ) Density (g / cm ³ )

20 C 20 C 20 C 20 C -5 C -5 C no no no no yes yes

3 620 3

1.05

-20 C -20 C -2Of -20 C -20C -20 C -IOC -IOC -IOC -20 C -IOC yes yes yes yes yes yes yes yes yes yes

4320 4 230 3 860 4 010 4 390 4 360 4 530 4 150 4 010 4 290 4

444444 4 3243

1.Π 1.14 1.14 1.10 1.16 1.16 1.22 1.14 1.16 1.12 1.16

Remarks:

') Number of the emulsifier:

(1) butyl stearate.

(2) Polyoxyethylene oidccylamine.

(3) alkyl (coconut oil) phosphate.

(4) AlkyC coconut oil-Dulkylnmid.

(5) Sorbltansesciuioleut.

(6) sorbitan monopalmitate.

(7) Sorbltan monooleate.

² ) Phenolic resin hollow microspheres /. ^} ) Ν, Ν'-Dinitrosopentamethylenetetriimin.

■ *) "ZB" (collapse) and "good" denote the state of the emulsion after the temperature cycle had been carried out the specified times, where "ZB" (= collapse) indicates that the emulsion had broken down and "good" that the emulsion condition was maintained. The numbers indicate the number of temperature cycles.

⁵ ) The number shows the sample temperature when the initial ignition test is carried out at a low temperature, "no" shows that no detonation takes place, "yes" shows that detonation takes place

takes place.
'') The figures show the value if the detonation takes place during the initial ignition test at low temperature.

⁷ ) The numbers show the value if the test is carried out three times and the receptacles detonate all three times.

⁸ ) NM ■ * Ntromethane. NC »nitrocellulose.

The results obtained in Comparative Examples and Examples are discussed below. at Comparative Examples 1, 2, 3 and 4 were butyl stearate, polyoxyethylene octadecylamine, alkyl (coconut oil) phosphate or alkyl (coconut oil) alkylolamide is used as an emulsifier, and the emulsions were prepared according to the manufacturing process described. However, when the temperature cycle test was carried out the emulsions collapsed after three, four, four and three times, respectively. In the comparative examples 5 and 6 were W / O disintegrant emulsions using sorbitan surfactant compounds prepared in the manner described above. When these explosive mixtures den were subjected to the above tests, the temperature cycle test gave good results achieved, but the detonability at low temperature, the explosion speed and the value of the Air gap tests were poor, with the latter being the worst.

In Example 1, a disintegrant using sorbitan is explained as an emulsifier which contains approximately 15% nitromethane and like in temperature cycle test results provides as according to Comparative Examples 5 and 6, but Betonation occurred at - 20 ⁰ C, which Explosionsgeschwirdigkeit is 4320 m / s, and the value for the air gap test is four times, so that this disintegrant is to be regarded as excellent.

Examples 2, 3 and 4 illustrate W / O disintegrant emulsions, those with the same emulsifier as in Example 1 and with hollow microspheres synthetic resin, shirasu and with N, N'-dinitrosopentamethylene tetramine as density control agents according to the manufacturing process described above

driving had been prepared. Its properties remained even after performing the ten times Temperature cycle tests unchanged, and the ignition test with electric detonators No. 6 resulted Explosion speeds of 4230 m / s, 3860 m / s and 4010 m / s. The reason that when using of hollow microspheres made of Shirasu, the explosion speed is low due to the fact that the particle size of the shirasu beads is larger than that of hollow glass microbeads.

According to Examples 5 and 6, disintegrants were made using sorbitan monopalmitate and Sorbitan monooleate produced as an emulsifier, with the same results as in Examples 1 to 4 were obtained. In Example 7, the amount of density control agent used was slightly less than in the other examples, so that the density of the disintegrant emulsions was naturally somewhat greater, but the quality of this disintegrant was largely the same as that of the other examples.

In Examples 8 and 9, the content of nitromethane was 8.4% and 5.4%, respectively, and the amount of Sensitizer was degraded, but the results of these examples were significantly better than that of the comparative examples.

In Example 10, hollow glass microspheres were formed along with a chemical foaming agent was used, with the same excellent results as the other examples.

From the foregoing comparative examples and examples, it is assured that the invention is excellent Storable W / O disintegrant emulsions that detonate well at low temperatures and have a good explosion speed and make sympathetic detonation available in a way that was previously unattainable.

Claims (5)

Patent claims: 1. Water-in-oil disintegrant emulsions from a) Ammonium nitrate and possibly other inorganic oxidizing salts, b) water, c) at least one oil or wax, d) one surfactant sorbitan fatty acid ester and e) a density control agent in the form of free or enclosed gas bubbles, characterized in that the emulsion is a through Mixing nitromethane with a gelling agent, gelled nitromethane and hollow microspheres and / or contains vesicles formed by means of a chemical foaming agent 2. Water-in-oil disintegrant emulsion according to claim 1, characterized in that the chemical foaming agent is a mixture of alkali metal borohydride or sodium nitrite with urea, Ν, Ν'-dinitrosopentamethylenetetramine, azodicarbonamide or azobisisobutyronitrile 3. Water-in-oil disintegrant emulsion according to claim 1, characterized in that the gelling agent for nitromethane is nitrocellulose 4. water-in-oil disintegrant emulsion according to claim 1, characterized in that it is 1 to 10 Contains percent by weight hollow microspheres 5. water-in-oil disintegrant emulsion according to claim 1, characterized in that it is 0.1 to 2 Contains% by weight of the chemical foaming agent